Field of the Invention
The present invention relates generally to the use of a luminescent compound radiated by energy propagated from the side of an optical fiber. One embodiment of the invention involves a display matrix made from coincidentally-excited phosphors. Another embodiment involves an optical switch.
Desktop computer monitors, laptop computers, televisions, and a wide variety of electronic devices incorporate displays. These displays are often of a cathode ray tube (CRT) or liquid crystal display construction. An example of a liquid crystal display panel is described by Funada, et al. in U.S. Pat. No. 4,231,640. The conventional construction of displays has typically involved high-voltage components and the emission of electromagnetic radiation and electromagnetic interference (EMI) from the display panel. Size and weight characteristics of conventional displays often make portability difficult or inconvenient. Also, durability of the display can be troublesome, due to the high number of electronic parts, or alignment required of various components.
There is currently no display technology that can provide a very thin, light and durable display panel that produces no electromagnetic interference or noise. Even a phosphor-based display has typically involved a complex construction involving variety of transistors, pixel drivers, electrodes and line or column electrical wire.
There are some display technologies that involve optical fibers adapted to emit visible light from the side of the optical fibers. However, these technologies are limited in that each optical fiber is either "on" or "off," causing an entire row of notches to emit the visible light transmitted through the fiber simultaneously. Each row of notches is also limited to the same color of visible light transmitted through the common optical fiber. None of these technologies combine luminescent materials with side-emitting optical fibers.
U.S. Pat. No. 5,432,876 discloses an optical fiber having a light emitting region to propagate light from an optical fiber in a preselected direction. One embodiment of '876 involves mounting of optical fibers to a panel so as to form a substantially parallel array. In one embodiment, a liquid crystal shutter array (LCS) is formed in front of the substantially parallel array so as to block unwanted notch emissions from view. However, '876 only teaches the redirection of light from the notch of an optical fiber and not the illumination of a luminescent material.
U.S. Pat. No. 5,659,643 discloses a notched fiber array illumination device. '643 is similarly limited to only teaching the redirection of light from an optical fiber, but does teach a Fresnel lens or other beam turning device can be used to further redirect light emitted from the notch of an optical fiber.